Convert chr to time format using chorn - r

Question

I am trying to transform my date dataset from chr to time format.
Here is my code :
time<-f1%>%
mutate(`ymd_hms(Timestamp)`=strftime(f1$`ymd_hms(Timestamp)`, tz="GMT", format = "%H:%M:%S"))%>%
transform(as.numeric(f1$SpotPrice))
chron(times=f1$`ymd_hms(Timestamp)`)
its showing error:
Error in chron(., times = f1$`ymd_hms(Timestamp)`) :
. and f1$`ymd_hms(Timestamp)` must have equal lengths
if i comment it
time<-f1%>%
mutate(`ymd_hms(Timestamp)`=strftime(f1$`ymd_hms(Timestamp)`, tz="GMT", format = "%H:%M:%S"))%>%
transform(as.numeric(f1$SpotPrice))
#chron(times=f1$`ymd_hms(Timestamp)`)
output is
'data.frame': 10078 obs. of 4 variables:
$ InstanceType : chr " a1.2xlarge" " a1.2xlarge" " a1.2xlarge" " a1.4xlarge" ...
$ ProductDescription: chr " Linux/UNIX" " Red Hat Enterprise Linux" " SUSE Linux" " Linux/UNIX" ...
$ SpotPrice : num 0.0671 0.1971 0.2171 0.1343 0.2643 ...
$ ymd_hms(Timestamp): chr "06:17:23" "06:17:23" "06:17:23" "12:15:54" ...
Also but i use this commend as a single variable as follows:
f2<-chron(times=DfUse$`ymd_hms(Timestamp)`)
it works and shows the output
'times' num [1:10078] 06:17:23 06:17:23 06:17:23 12:15:54 12:15:54 ...
- attr(*, "format")= chr "h:m:s"`
but i want to pipe it with my whole dataset not to use it alone as a single variable.
Thanks in advance.

Answer 1

There are few syntax errors and room for improvement in the code.
Although having ymd_hms(Timestamp) = on the left hand side works but you don't need that since it creates a column with that name. Only using Timestamp should be good.
Don't use $ in dplyr pipe.
Usually it is better to keep base R functions and dplyr functions separate. transform is in base R but you can use the same mutate pipe to turn SpotPrice to numeric.
library(dplyr)
time<-f1%>%
mutate(Timestamp = strftime(ymd_hms(Timestamp), tz="GMT", format = "%H:%M:%S"),
SpotPrice = as.numeric(SpotPrice),
Timestamp = chron::chron(times=Timestamp))